Cogito wrote:
Tom, are you experienced with Glock 19?
Yesterday, I tried FN 509 and Glock 19. I found Glock more difficult to aim.
Sashi,
IMHO. there are probably two factors that contributed to your initial experience: Grip Angle and Sight Picture.
Here's a good post about grip angles:
http://www.warriortalk.com/showthread.php?140421-22-degree-grip-angle-of-the-glock-and-18-degree-Non-OEM-framesLots of people don't like the 22 degree Glock grip angle at first, but it's easy to get used to it, as Gabriel Suarez points out. Remember that name.......
Lots of people also have some difficulty when they first encounter the typical Glock sights. Again, you can get used to it - millions of people have.

FWIW, lots of people REALLY like the latest FN pistols, with good reason IMHO. They are both high quality products, but the Glock has two deviations from standard design practice that have an impact on the user interface which is immediately noticeable. They are not deal breakers, but as you experienced they really stand out when you first start using it.